A Low-Complexity Versatile Beamforming Method for Multiple Parametric Arrays

The application of multiple parametric arays (MPAs) has been increasingly prominent in recent years due to the high directivity of parametric arrays. However, existing beamforming methods for MPAs are limited to special scenarios, such as narrow-edged beamforming, or have high complexity, such as requiring numerous acoustic transfer function (ATF) identifications. This paper proposes a low-complexity versatile beamforming method based on the transitive relationship among ATFs. For N parametric arrays, the number of identified ATFs can be reduced from N2 to N through interpolation and flipping. Moreover, by neglecting the less affected part in the acoustic field structure, the number of identified ATFs can be reduced to less than N. On the basis of ATF matrix estimated, the desired acoustic field can be generated by optimizing the emission weight coefficient. The accuracy of ATF estimation is verified through the precise reconstruction of the acoustic field. Even when the number of identified ATFs does not exceed N, the desired acoustic field of different types of beam patterns can be formed correctly. The beamforming effects of MPAs confirm the low-complexity and versatility of the proposed method, offering a highly feasible solution for acoustic field control.